Answer: 
Step-by-step explanation:
Given : Sample size : 
Sample mean : 
Standard deviation : 
Significance level : 
Critical value : 
Formula to find the confidence interval for population mean :-

Hence, a 90% confidence interval estimate of the population mean of all students = 
Answer:
Therefore,

Step-by-step explanation:
Given:
![A=\left[\begin{array}{ccc}3&6&9\\2&4&8\\\end{array}\right]](https://tex.z-dn.net/?f=A%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D3%266%269%5C%5C2%264%268%5C%5C%5Cend%7Barray%7D%5Cright%5D)
To Find:
a₂₁ = ?
Solution:
Let,
![A=\left[\begin{array}{ccc}a_{11}&a_{12}&a_{13}\\a_{21}&a_{22}&a_{23}\\\end{array}\right]](https://tex.z-dn.net/?f=A%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Da_%7B11%7D%26a_%7B12%7D%26a_%7B13%7D%5C%5Ca_%7B21%7D%26a_%7B22%7D%26a_%7B23%7D%5C%5C%5Cend%7Barray%7D%5Cright%5D)
We require ' a₂₁ ' i.e Second Row First Column Element
So on Comparing we get
∴ 
Therefore,

Answer:
wish i can help
Step-by-step explanation:
Answer:
cant see picture but it is an easy question based on equilateral that has 3 identical angles and is congruent. A Scalene has odd sides and is not congruent and an isosceles has two sides identical. You can also get two type of right angled triangle only 45 45 plus 90 for right angle would be be congruent
Step-by-step explanation: